1. Field of the Invention
The present invention generally relates to safe mechanisms, and more particularly relates to safe mechanisms which are resistant to drilling, cutting, and pounding attacks from outside the safe.
2. Background Information
Locking mechanisms for securing safe doors have existed for many years, and there are large varieties of techniques utilized in such locking mechanisms. Many of such locking mechanisms strive to make it hard for a person to break into a safe by hammering or drilling. When a person tries to break into a safe, they may try to attack the lock mechanism in order to open the safe door. Since most locks have a locking mechanism such as a keyed tumbler, a combination lock, a keypad lock, a fingerprint or other biometric recognition lock, or other locking devices exposed on the surface of the lock, these are points of attack. Many locks also have a handle which is turned to release the safe door and open it. The handle and the handle shaft that goes through the safe door are other points of attack for drilling and hammering. The mechanisms behind the handle shaft and the lock mechanisms are also subject to attack by drilling and hammering.
Many safe designs are configured to deter such attacks on the lock, the handle, the handle shaft, and the mechanisms behind both of these attack points. One way to protect the lock mechanisms behind the handle shaft is to provide a secure support strap behind them. Typically, the shaft would extend through the safe door, and be supported and attached to a support strap which is sometimes placed at an angle across the other parts of the lock mechanism, such as extending from a seven o""clock position to a two o""clock position. A disadvantage of this type of support for the shaft is that if the handle or the handle shaft is struck with a heavy blow, the energy of the blow is transmitted through the safe door to the support strap. With sufficient blows, the support strap can give way and this can give rise to the lock mechanism being defeated.
Another way that safes can be attacked is by drilling out the shaft which is attached to the handle. The shaft can easily be cut off flush to the face of the safe door, and then drilled straight through the shaft, basically eliminating the shaft. If the safe mechanism is not designed to defeat this, drilling out the shaft can lead to the defeat of the locking mechanism. Another part of the safe that is subject to attack is the linkage between the shaft and the pins which extend into the doorframe of the safe. One way to sever these linkages is to use a drift drill to cut sideways through such linkages. A safe needs to be designed to make such cutting or drilling of the linkages difficult.
The safe can also be attacked by drilling out the lock mechanism, such as the keyed tumblers or the combination lock and also drilling or pounding on the tongue which extends from the lock mechanism, and which causes the mechanism to be locked. Pounding on the lock tongue to drive it out of engagement should not result in failure of the lock system.
To address the modes of attack on the lock mechanism, it is an object of the invention to provide a safe mechanism which jams in the locked position if the shaft is drilled out. It is the further object of the invention to provide a safe mechanism that jams in the locked position if the tongue of the lock mechanism is driven out of position, damaged, or deformed, or if any parts of the linkages between the crank or shaft and the locking pins are drilled out, or cut off. It is a further object of the invention to provide a shaft which transmits force to the safe door rather than to the mechanism behind the safe door, when pounded. It is a further object of the invention to provide an anti-drill protection for the lock mechanism itself and nearby components. It is a further objective to provide a safe mechanism which meets all the above requirements and is also simpler to manufacture and of a narrow profile, so that the safe door can be relatively thin.
These and other objects are accomplished by the safe mechanism disclosed herein. The safe mechanism is designed to be used with a safe which typically includes a separately manufactured lock mechanism, a safe door, and a slider with one or more attached locking pins. In many safe configurations, the slider is a linear piece with locking pins attached, which extend into a frame surrounding the safe door, and thus serves to secure the door in place. The safe mechanism includes a link arm which attaches to the slider of the safe door. The link arm has a first end and second end, and a link arm body in which a slot is defined. The link arm is attached at its second end to the slider. Thus movement of the link arm causes movement of the slider, and the locking pins into and out of engagement with the frame of the door.
The safe mechanism of the invention also includes a crank assembly. The crank assembly includes a crankshaft, a crank plate which is attached to the crankshaft, and a crank slider pin attached to the crank plate. The crank plate is mounted adjacent to the link arm, so that the slider pin engages the slot in the link arm. When the crank plate is rotated about the crankshaft, it thus causes lateral movement of the link arm by movement of the crank slider pin in the slot of the link arm. The crank plate is configured for engagement with the lock mechanism. Thus, when the lock is engaged, the crank plate is prevented from rotating. When the lock mechanism is disengaged, the crank plate may rotate around the crankshaft.
In one configuration of the safe mechanism, the slot which is defined in the link arm, has a vertical section and a horizontal section, which join each other at ninety degrees (90xc2x0). In this configuration of the safe mechanism, the crankshaft extends through the horizontal section of the slot. The slot in the link arm can be recessed into the link arm, or it can penetrate completely through the body of the link arm. In the configuration in which the slot extends completely through the link arm, the crank slider pin can also extend completely through the slot and the link arm body. The crank slider pin can also extend partially into the slot, if the slot is recessed into the link arm but does not pass all the way through it. The crankshaft penetrates through the safe door and is attached to a handle which is on the exterior side of the safe door. This handle can take a variety of configurations, and can be a wheel with one or more spokes which attaches to the crankshaft, or it can be a lever which extends to one or both sides of the center of the crankshaft, or the handle can be configured as spokes of a wheel, without the wheel itself, or it can be a knob or other configuration which allow a person outside the safe to turn the handle, and the attached crankshaft.
One configuration of the safe mechanism is one in which the crank plate includes a first notch, which is configured for engagement with the tongue of the lock mechanism. When the tongue of the lock mechanism is extended in a locked position, it engages the first notch of the crank plate. When the tongue of the lock mechanism is retracted, in an open position, then the crank plate may rotate freely. The safe may also include a second notch which is positioned to be engageable with a re-locker. The re-locker is a device which is normally kept in a retracted position. When certain triggers are activated, the re-locker is activated and serves as a secondary locking mechanism, or as a back up to the lock mechanism.
One embodiment of the safe mechanism can also include a crankshaft which includes a shoulder which is configured for mounting on the exterior of the safe door. In this way, if pressure from the exterior is applied to the crankshaft, that pressure is transferred to the safe door by means of the shoulder built into the crankshaft. For instance, if a person breaking into the safe pounded on the exterior end of the crankshaft with a hammer, the force from the hammer blows would press the shoulder into the safe door, and would not press the interior end of the crankshaft against interior components. This can be accomplished by a recess around the crankshaft in the safe door, in which the shoulder is completely or partially recessed. This can also be accomplished by use of a backing piece which is mounted around the crankshaft hole and on the inside surface of the safe door. The shoulder would then press against the backing piece, which becomes an extension of the safe door. In this configuration, the crank passage in the backing piece would be sized smaller than the crankshaft shoulder in order to transfer pressure from the shoulder into the safe door. When used with a backing piece, the shoulder can be fully or partially recessed in the crank passage in the safe door.
Another configuration of the safe mechanism is for use with a safe as described above, which includes a re-locker mechanism which acts as secondary lock to the lock mechanism, and which, when activated, extends a re-locking tool for engagement with both the crank plate and the link arm. The purpose of this is to provide a higher level of security so that if the re-locking of the crank plate can be defeated, the link arm will still be locked in place. If the link arm were freed, then the crank arm would still be locked in place. In order to defeat this re-locker mechanism, engagement of the re-locker with both the crank plate and the link arm would have to be defeated. The re-locking tool can be a rectangular bar which is extendable for engagement with the crank plate and the link arm. The re-locker mechanism can operate by the generally rectangular bar engaging a re-locker notch in the crank plate and a re-locker notch in the link arm.
One of the triggers for activation of the re-locker mechanism is a deflection of the lock mechanism from its normal operating position. Another mechanism for triggering the re-locker mechanism is deflection of the lock tongue of the lock mechanism from its normal engaged position. Yet another trigger means for activation of the re-locker mechanism is deflection of the protective cage. Yet another trigger means for activation of the re-locker mechanism is deflection of the back of the lock mechanism.
Another embodiment of the safe mechanism of the invention is one having the features listed below. This embodiment of the safe mechanism includes a link arm whose body includes a first and a second end. The second end is attached to a slider, and when the link arm moves back and forth, the slider also moves back and forth, and pushes linking pins which are attached to the slider into engagement with the doorframe of the safe. This version also includes a crank assembly which includes a crankshaft with a shoulder section built into it, a crank plate with a first and a second notch, and crank slider pin which is attached to the crank plate and extends out from the crank plate. The link arm body includes a notch with a horizontal section and a vertical section which are joined to each other at approximately a ninety-degree (90xc2x0) angle. The crank plate is mounted adjacent to the link arm, so that the crank slider pin of the crank plate fits in the slot of the link arm, and the crankshaft also passes through the slot in the link arm. As the crank plate is rotated, the movement of the crank slider pin in the slot of the link arm causes the link arm to move laterally, thus engaging and disengaging the locking pins which are attached to the slider, which itself is attached to the link arm. This version of the safe mechanism also includes a re-locker mechanism, which, when released by an arming plate 78, engages both the crank plate and the link arm, by a generally rectangular re-locker bar engaging a notch in the crank plate and the link arm.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive.